Accumulator injection system



.D. E. MEITZLER ACUMULATOR. INJECTION SYSTEM Feb. 8, 1949.

4 Sheets-Sheet 1 f Filed May l1.1. y 1943 yvEN-rcn 'v ATTORNEY Feb. 8, 1949. D. E, ME|TZLER 2,461,222

AccuMuLA'x-on INJECTION SYSTEM Filed May 11, 1943 4 sheets-sheet 2 INVENTOR Flc. 2 mdff mim ' ATTORNEY'l Feb. 8,1949. DQ E, MEITZLER 2,461,222

i ACCUMULATOR INJECTION SYSTEM Y Filed may 11, 194s 4 Sheets-Sheet 3 IIO FIG.

Feb. 8, 1949. A D, E, ME|TZ| ER 2,461,222

ACCUMLATOR INJECTION SYSTEM Filed May 11, 1943 4 Smets-sheet 4 INVENTOR @rg/HMM ATTORNEY b Patented Feb. 8, 1949 Donald E. Manier,

to United Aircraft Conn., a corporation of Corporation,

Manchester, Conn., asignar East Hartford, Delaware Replication my: ii', 194s. sei-isi No. 486.625

' c claims. (ci. 23o-5s) This invention relates to fuel injection appara-4 tus, particularly for free-piston engine-and-compressor units.v

.In free-piston units the opposed pistons may be maintained at equal distances from the center of the engine cylinder by a restraining linkage which includes racksextending fromthe. pistons, and a pinion engaging the racks.` Such-linkages have served to actuate fuel pumps. Theaxis of the interconnecting pinion is normally at right angles to the axis of the .engine cylinder. If the pump also extendsradially, actuation of the pump from the pinion is dimcult. An object voi' this invention is to actuate a radially positioned pump from the oscillating -pinion by a simple .driving connection; Y

Another feature is the mounting ofthe pump coaxially with the restraining Apinion and the actuating ofthe pump bythe oscillation -of the pinion. Still anotherfeature is the 'support of the pinion by an external bearing in such manner that the pump may extend and be actuated thereby.

Other objects andadvantages will be apparent from the specincation and claims, and from the accompanying drawing which illustrates what is through the pinion now considered to bea preferred embodimentof the invention.

Fig. :.1 is. a sectionalrview through the freepiston engine-and-compressor unit showing the restraining linkage.

A Fig. 2 is .a sectional view through the injection device and the supporting bracket.

Fig. 3 is a sectional view on line3-3 of Fig. 2 showing the rack drive.

Fig. 4 is a fragmentary section of the injection plunger and surrounding casing, showing the plunger at the start of its injection stroke.

Fig. 5 is a sectional view on a larger scale of a part of the device of Fig. 2.

The unit shown includes an engine cylinder Il! having reciprocating pistons I2 and M to which compressor pistons i6 and i8 in cylinders 20 and 22 are integrally connected. Sleeves 2li and 26 attached to the compressor pistonscomplete the `n'eciprocating piston assemblies. The sleeves in combi ation with stationary pistons 28 and 39 form air spr\ing cylinders.

.The piston emblies are moved apart by the burning 0f fuel injected into engine cylinder le by one or more devic Air compressed in the air spring cylinders. onzthe verastroke returns the piston assemblies. The assemblies are always 2 a, the engine cylinder by a linkage including racks 3l on the compressor pistons meshing with a pinion 3C (Figs. 2 and 3).

Intake manifold 38 conducts air to intake valves 40 through which air alternately enters opposite ends of the compressor cylinders.' The compressed air leaves the cylinders through discharge valves l I2, also at opposite ends of the compressor cyl' inders.' and passes through scavenge manifold 44, through ports 4S and 4B which are uncoveredby pistons I2 and Il at the end of the power stroke'v thereby permitting air to be blown through the engine cylinder and exhaust ports 50 and 52 into exhaust manifold 54.

15 Pinion 36 is supported in a housing 56 forming g part of the injection device 32 which is mounted in a tubular bracket 58. The pinion is integral with a shaft journalled in the housing, and

supported by a ring 64 in -housing 56. A radial v 20 ange 86.0n the shaft which is held between the end of bearing ring 64 and a thrust ring 68 prevents endwise movement of the pinion.'

The innerY surface of shaft 60 has a helix'lll 25 engaging several spaced shoes 12 on a cupv 14. This cup ispositioned over a casing 16 in which injection plunger 18 is movable.A A coil spring urges cup 74 axially to hold the shoes in contact with the helix. y As pinion 36 is oscillated by racks Il, plunger 18 is moved longitudinally in its bore 82 in casing 16, since the end of plunger 18 is held against the cup by a coil spring 84.

. The injection system may be the accumulator 1 type, as shown. Casing 16 may haveA opposed by a passage 90, Fig. 5. Fuel from thee'nd'of bore 82 reaches the chambers through a groove 92 in an accumulator valve 94 which slides in a bore 96 in a ring 98 in casing 16. Fuel escapes from accumulator chambers through a passage |00 and past a check valve "i2-to the nozzle |04. The accumulator valve 94 moves endwise to engage a seat |06 atthe end of passage |00 or a seat |08 in ring 98 for closing groove 92.

As the plunger 'I8 is 'moved on the injection stroke (to the right from the position of Fig. 4), fuel which entered the end of bore 82 through an inlet port lill is forced into the accumulator chambers through groove 92 until a discharge port H2 is uncovered by a groove H4 in the plunger. This groove H4 is connected to the head of the plungerby passages IIS and H8. When port H2 is uncovered (plunger position of Fig. 2), the pressure at the end of the plunger maintained at equal distances from\tlre centerjof 55' drops suddenly so that the pressure acting on accumulator chambers 86 and 88 interconnected.

monaca valve u@ wnoia it against seat m is relieved.

This valve then moves against seat |08 and fuel to the pinion axis. and cooperating means condischarges past check valve |92 and through nozzle |24.

The entire fuel injection system is thus mounted within pinion 36 which forms a part of the restraining linkage and the injection plunger is actuated by the oscillation of'- the pinion as the engine pistons. reciprocate.

The injection device is ,mounted as a unit in tubular bracket 58. Housing 66 with the device assembled therein is held in the bracket by studs |29. These studs |28 pass .through hollow studs y |22 which hold a cap |24 on housing 66. Cap |24 also has mounted therein a filter element |26, the end of which communicates with passages |23 and |29 in cap |24 and housing 5I through which fuel reaches inlet port IIII. Fuel is delivered to the filter through a passageillin bracket il and passages |32 and |34 in housing 66 and cap |24. With this arrangement the filter element is removed as a unit with the injection device. Thus, any foreign matter that may be in passages |38 or |32 'when a device is dlsmounted from bracket 58 will be filtered out before the fuel reaches the injection pump. Gaskets |36 and |38 may be used to prevent leakage of fuel.

Cap |24 may also have splines |40 interengaglng splines on cup 'I4 to prevent rotation of the cup during its reciprocation.

It is to be understood that the inventionl is not limited .to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as defined by thefollowin'g claims.

k I claim:

l. A free-piston compressor having opposed pistons and a restraining linkage connecting said pistons and including an oscillatory pinion, in combination with a fuel injection pump including `a casing having a bore, a plunger in said bore and coaxial with the pinion, said pinion surrounding said casing with the plunger concentric to the pinion axis, and cooperating means connecting the pump plunger and pinion for reciprocating the pump plunger in response to the pinion oscillation.

2. A free-piston compressor having opposed pistons and a. restraining linkage connecting said pistons and including an oscillatory pinion, in combination with a y fuel injection pump, said pump including a casing at least partially within and surrounded by said pinion and having a. .bore coaxial with the pinion, a reciprocating plunger in said :bore and also coaxial with the pinion, a thrust cup engaging the plunger,` and means interconnecting the pinion and the thrust cup for pinion oscillates.

3. A freepiston\compressor having opposed vnecting the pump plunger and pinion for reciprocating the plunger in response to pinion oscillation, said means including a helix element and cooperating elements engaging said helix element.

. one of said elements being connected to the pinion and the other being connected to the plunger.

4. A free-piston compressor having opposed pistons and a restraining linkage connecting said pistons and including an oscillatory pinion, 1n combination with a fuel injection pump including a casing having a bore, a plunger in said bore and coaxial with the pinion, said pinion surrounding said casing with the plunger concentric to the pinion axis, and cooperating means connecting the pump plunger and pinion for reciprocating the plunger in response to the-oscillation of the pinion, said means including a helix on the pinion and cooperating lugs engaging the helix and con-` nected to the plunger.

5. A tree-piston compressor having opposed pistons, and a. restraining linkage connecting said pistons and including an oscillatory pinion. in combination with a iuel injection device including a casing having a bore, and 9, plunger reciprocating in said bore, said device being surrounded by the pinion, the axis of the pinion being substantially concentric with the longitudinal axis of the plunger.

6. A free-piston compressor having opposed pistons, and a restraining linkage connecting said pistons and including an oscillatory pinion, in combination with a fuel injection device including a casing having a bore, and aplunger reciprocating in said bore, said device being surrounded by the pinion, the axis of the pinion being substantially concentric with the longitudinal axis of the plunger, and means responsive to oscillation of the pinion for reciprocating the plunger causing the injection of fuel by said device.

. reciprocating said cup and said plunger as the pistons and a restraining linkage connecting said f pistons-and including an oscillatory pinion, in combination with a fuel injection pump including a casing having a bore, a plunger in said bore and coaxial with the pinion, said pinionsur- DONALD E. MEII'ZLER REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES -PATENTS Number` Name Date 1,943,718 Bell Jan. 16, 1934 2,016,613 Pescara v Oct. 8, 1935 2,038,442 Pescara Apr. 21, 1936 2,064,976 Janicke Dec. 22, 1936 2,102,121 Janicke Dec. 14, 1937 2,112,368 Janicke Mar. 29, 1938 2,132,083 Pescara -L Oct. 4, 1938 2,222,260 Janicke Nov, 19, 1940 2,223,759 Dillstrom Dec. 3, 1940 2,344,058 Pescara Mar. 14, 1944' 2,368,013 Ford Jan. 23, 1945 FOREIGN PATENTS Number Country Date 351,747 Germany Apr. 15, 1922 

